End-of-track radiolytical processes and radical formation in positive muon irradiated acetone

Abstract

The radiolytical processes near the end of the track of energetic positive muons stopping in acetone are investigated by means of the muon spin rotation technique. The residual muon polarization and phase on the muon precession frequencies in muonated radicals demonstrate two parallel channels for radical formation. Of the Muons, 41% are found to end up in the radical, (CH 3) 2COMu. Two-thirds of it have muonium (Mu ≡ μ +e −) with a lifetime of 0.1 ns as precursor, one-third diamagnetic Mu + with a lifetime of 3 ns. The average initial separation of Mu + from its closest spur electron is estimated to be 3–4 nm.